I am betfair software vendor and received the following email:
Hi Stefan,
Thanks for your response.
Very few vendors have decided to offer their products for free and hence obtain a free full access subscription. We have only offered this to those who proposed to provide all software free of charge.
The vast majority of software vendors pay to access the Full Access API and charge their end users to access their service. Other vendors have decided to build their applications using the Free API because their products do not require full access. Some vendors using the Free API software vendor license choose to provide their products free of charge and others decide to charge.
If you are happy to provide, develop, and support your products free of charge, please confirm this and let us know when you have removed the subscription model from your website relating to your products.
Kind Regards Neil BDP Support
When I started with my project I had to pay for full transactional betfair api access from the first month of starting development and I do so from March 2007.
Those who want to start building betfair api product or using personal full access api could save 2400 GBP per year just by declaring their product to be free, or offering free product of any kind.
I am about to change my subscription model for all my products to donation model and share one of my trading application (BXTrader) as the open source.